Process for producing yarns showing novel varying color effects

ABSTRACT

Yarns showing novel color effects varying along their length are made by feeding a thermoplastic yarn into a confined space, so forming a long stack of uniform cross section of folded yarn in the said space, by means of a jet of fluid at a temperature sufficient to set the resulting crimp in the yarn, and feeding a dye solution, preferably two or more dye solutions at different locations to the same cross section of the stack, under conditions such that the resulting intensity of color of the yarn due to each dye falls off across the stack from the point or points of application.

United States Patent Guillermin et al.

[54] PROCESS FOR PRODUCING YARNS SHOWING NOVEL VARYING COLOR EFFECTS Rene Guillermin, Bron; Jean Joly, Brindas, both of France Assignee: Societa Rhodiaceta, Paris, France Filed: Nov. 25, 1969 Appl. No.: 879,880

Related U.S. Application Data Continuation-in-part of Ser. No. 649,089, June I6, 1967.

Inventors:

Foreign Application Priority Data 1 Feb.29,1972

Primary Examiner-Donald Levy Attorney-Cushman, Darby & Cushman [5 7] ABSTRACT Yarns showing novel color effects varying along their length are made by feeding a thermoplastic yarn into a confined space, so forming a long stack of uniform cross section of folded yarn in the said space, by means of a jet of fluid at a temperature sufficient to set the resulting crimp in the yarn, and feeding a dye solution, preferably two or more dye solutions at different locations to the same cross section of the stack, under conditions such that the resulting intensity of color of the yarn due to each dye falls off across the stack from the point or points of application.

- 2 Claims, 2 Drawing Figures Patented Feb. 29, 1972 I III/1 5 4 PROCESS FOR PRODUCING YARNS SHOWING NOVEL VARYING COLOR EFFECTS This invention relates to a process for producing colored yarns having properties varying in the longitudinal direction and optionally also in the transverse direction, and is a continuation in part of our application Ser. No. 649,089, filed June 16, 1967.

The term yarn is to be understood as meaning any continuous length of substantially unidirectional textile material, regardless of its structure, which can be used for textile manufacture; thus a yarn may consist of one or a number of continuous filaments, or of discontinuous (staple) fibers.

Yarns having along their length zones of different appearance can be used to produce woven fabrics, knitted fabrics, carpets and other textile articles with fancy effects which are of interest from an aesthetic point of view.

Yarns of vegetable or animal origin naturally have properties which are not strictly uniform over the whole of their length and/or their diameter and special effects can be achieved by working on these differences.

On the other hand artificial and synthetic yarns are usually characterized by a smooth and uniform appearance and by uniform properties, and if such effects are to be achieved it is necessary to resort to special techniques to create zones of irregular appearance.

The properties and appearance modified by various processes.

It is for example possible by carrying out the extrusion and/or the stretching under variable speed or temperature conditions to produce filaments of irregular gauge, usually called flake yarns; the length, frequency and diameter of the flakes, that is to say of the zones in which the filaments have a larger diameter, can vary within wide limits.

Yarns having zones of different shades and/or colors may be of synthetic yarns can be obtained by printing these flake yarns, presented in the form of layers, by techniques similar to those used for printing woven fabrics. However this type of process is only successfully applicable to high-gauge yams such as those used in the manufacture of carpets.

It is known that the dyeing properties of certain yarns can be irregularly modified by subjecting successive lengths of these yarns to heat treatments of different intensity or duration; in a subsequent dying treatment the dyestuffs are not taken up homogeneously and articles having camaieu effects are obtained; it is difficult, if not impossible, to obtain effects with different shades by this process.

The present invention comprises a process for the continuous production of a crimped colored yarn in which the yarn is simultaneously crimped and dyed, the crimping being effected by folding and compressing the yarn in the form of a stack in an enclosed space into which it is fed by means of a current of a compressed fluid which is at a temperature at which the crimp is set in the yarn, part of the fluid escaping from a side of the enclosed space in a controlled fashion, and the rest forcing the packed yarn in and out of the enclosed space, and the dyeing being effected by applying continuously and regularly at at least one location laterally with respect to the stack a dye composition in such a way that the intensity of the color produced on the yarn decreases with increasing distance, over the cross section of the stack, from the location at which the composition is applied to the outside of the stack. Such a dyeing treatment is hereinafter referred to as a treatment which is heterogeneous with respect to the stack, or simply as a heterogeneous treatment.

The stack is produced within an enclosed space formed by a container, so that its shape and volume are constant throughout the process. The container is preferably in the shape of a cylinder and in particular a cylinder of revolution, but may also be in the shape of a parallelpiped.

The length and diameter of the container which defines the stack may vary within quite wide limits, and will generally be chosen as a function of the gauge of the yarn to be treated and optionally of the duration and intensity of the treatment which is to be carried out. The length/diameter ratio of the container will usually be between 5 and 100, but may be outside these limits. This choice may be dictated by the distribution of the zones of differing appearance which it is desired to produce on the yarn. Thus by a suitable choice of ratio, especially when the diameter of the stack is large, there may be produced any particular combination of zone length and frequency of change in the yarn.

The yarn is introduced at one end of the container by an injection nozzle fed with a fluid under pressure, which may be air or steam.

In order that the yarn should stack in the container it is necessary that at least for part of the time the yarn should be introduced into the container under overfeed conditions, and this should take place for a period which is the longer the greater the volume of the container, that is to say the volume of the stack which one wishes to produce. A slight overfeed may be maintained throughout the duration of the process, or overfeed may be stopped when the stack of yarn occupies the entire volume of the container.

The heterogeneous dye treatment may be effected in different ways. For example the treatment can be carried out with a degree of intensity such that the surface but not the core of the stack is affected, or it may be applied to one side only of the stack, at an intensity insufficient to cause the whole cross section to be affected, or to be equally affected.

However in the preferred method of working two or more streams of colorant are introduced simultaneously into the enclosed space through the wall thereof, at points differently oriented with respect to the axis of the stack, but preferably arranged so that the different streams impinge on the same cross section of the stack taken normal to its axis again in such a way that the effect on the yarn falls off across the cross section of the stack. In this method, provided the amount of colorant solution fed is sufficient to ensure that a residual amount penetrates right through the stack, each point in the cross section receives a different amount of each colorant. If the amount of colorant is less than this, part of the yarn may remain undyed, but although useful effects can be obtained in this way, it is in general less desirable. In either case the yarn vin the stack will present a whole range of colors, from the colors actually applied to innumerable combinations thereof differing in shade and depth.

The dyed stack can be collected in any suitable receptacle. In this case the stack as such need not be destroyed until later. On the other hand the yarn may be passed over one or more yarn guides to a winding up device, in which it is wound as a package on a support.

The process of the invention can be applied to any thermoplastic yarn which is strong enough to withstand the action of the current of fluid without breaking, for example to synthetic yarns having a basis of a polyamide, polyester,

polyolefine, or polyacrylic or polyvinyl compound. The yarns may have been stretched or may be stretched after the treatment, in which case the changes in shade and depth along the length of the yarn become more gradual and drawn out.

The invention is illustrated in the accompanying drawing, in which FIG. 1 represents schematically and in section one form of device in which the process can be carried out, and FIG. 2 represents similarly another such form of apparatus. The drawing will be referred to more particularly in the following illustrative Examples.

EXAMPLE 1 This Example describes, by reference to FIG. 1 of the accompanying drawing, one embodiment of the invention in which yarns of varying shade are produced.

A 1040 denier/60 filament polyhexamethylene adipamide yarn 3 is introduced at 200 m/minute, by means of a nozzle 1 fed by saturated steam under a pressure of 3.5 bars at inlet 2, into a container 4 consisting of a hollow metallic cylinder of internal diameter 8.6 mm. and length 15 cm.

At l cm. from the end at which the yarn enters, the cylinder is perforated by three sets of six orifices 5 of diameter 1 mm. arranged in a ring. The fluid used for introducing the yarn largely escapes through the orifices and gives rise to a stack 6 of folded yarn.

Three tubes 7 of diameter 1 mm., arranged at 120 to one another and connected to three reservoirs 8 each containing an aqueous solution comprising 10 g./liter of dyestuff, are mounted 50 mm. from the end of the cylinder.

One of the solutions is based on Foulon Brilliant Yellow 2 R sold by Francolor (C.I. 25,135), the second is based on Polar Orange R sold by Geigy (C.I. 22,195) and the third is based on Polar Brilliant Blue RAW (C.l. 61,585)

The dyestuff solutions deposit (before the outlet from the container) on to the yarn stack at the point where the three tubes end.

The yarn withdrawn from the stack is curled and varies in color, both from filament to filament and over the length of each filament. The shades observed in the yarn correspond not only to the dyestuffs used, but also to mixtures of the dyestuffs.

EXAMPLE 2 In this Example a device broadly similar to that of FIG. 1, and represented in FIG. 2, is used; it comprises a nozzle and a container consisting of a cylindrical metallic tube of internal diameter 12 mm. and length cm., perforated with three rings of six orifices of diameter 1 mm. Four solutions of dyestuffs are provided in four reservoirs 9 which together constitute a cylinder whose cross section is a circular ring concentric with the metallic tube. An outlet tube which opens out into the metallic tube 50 mm. from the outlet end of the yarn is fixed to the bottom of each of the reservoirs.

A yarn of 3 ends of polyhexamethylene adipamide each of l040 denier/60 filaments is introduced into the tubular container at 100 m/minute by means of the nozzle which is fed by saturated steam at 3.5 bars. This yarn stacks under the action of the lateral escape of the fluid.

The four aqueous solutions contained in the reservoirs, each contain 10 g./liter of dyestuff and are based respectively on:

Foulon Brilliant Yellow 2 R C.l. 25,135 Polar Orange R Cl. 22,l95 Alizarin Cyanin Green 1 G (1.1. 62,560 Polar Brilliant Blue RAW C.l. 61,585

They flow out through the four outlet tubes and deposit on the yarn stack,

After being withdrawn from the stack, a curled yarn is obtained whose shade varies from filament to filament and over the length of the filament.

4 EXAMPLE 3 Four thousand Denier/60 filament unstretched polyhexamethylene adipamide yarn is treated in an apparatus identical to that of Example 2, and using the same conditions as those there described.

After being withdrawn from the stack, the yarn is stretched four-fold; this stretching removes the curls and a noncurled printed-flake yarn is obtained.

EXAMPLE 4 Using the same apparatus as in Example l, a double polyhexamethylene adipamide yarn of two ends, each of 60 filaments and 1040 denier l dtex), is treated.

Three cold aqueous dye solutions are applied to the stack through the feed tube 7.

The operating conditions are:

Rate of feed of the yarn 400 meters/minute Pressure of saturated steam 7 kg./cm. Flow: 26 cc./mn. for each dye solution The three dye solutions are respectively:

Foulon Red J C1. 22,245

(concentration 20 cc./liter) Foulon Yellow 2 R C.l. 25,l35

(concentration 20 ccJliter) Polar Brilliant Blue C.l. st ,585

(concentration 30 cc.llitcr) A multicolored yarn is obtained.

We claim:

1. Process for the continuous production of a crimped, dyed synthetic thermoplastic yarn in which the yarn is simultaneously crimped and dyed, comprising feeding the yarn into an enclosed space by carrying the yarn on a current of compressed gas at a temperature at which the crimp of the yarn is set, folding and compressing the yarn in the form of a stack in the enclosed space, releasing part of the gas from a side of the enclosed space, dyeing the yarn by applying continuously and regularly to at least one location on a vertical side of the stack in the enclosed space a dye composition in a small quantity, so that the intensity of the color produced on the yarn decreases with increasing distance over the cross section of the stack from the location at which the composition is applied to the side of the stack, and forcing the packed yarn by said gas current out of the enclosed space.

2. Process according to claim 1 wherein at least two different dyeing solutions are applied at difierent locations to the same cross section of the stack, taken normal to the axis of the stack. 

2. Process according to claim 1 wherein at least two different dyeing solutions are applied at different locations to the same cross section of the stack, taken normal to the axis of the stack. 